Adaptive fuzzy fractional order PID control for 6-DOF quadrotor

In this paper, an adaptive fuzzy fractional order PID (AFFOPID) controller is proposed to stabilize the position translation and horizontal rotation of a six-degree-of-freedom (6-DOF) quadrotor. The controller combines the advantage of wide range of fractional order PID (FOPID) and the adaptive characteristics of fuzzy logic controller (FLC). Different from the conventional fuzzy logic controller, the fractional order differential and integral are introduced into the input and output variables. The resistance term is appended to the 6-DOF nonlinear dynamic model of the quadrotor, which is closer to the actual flight model. The parameters of the proposed AFFOPID are tuned using particle swarm optimization (PSO) algorithm to minimize the integral of time multiplied absolute error (ITAE) and overshoot. Performance focus is selected by setting the weight values. The simulations have been completed in MATLAB/Simulink environment and include step tracking and trajectory tracking, where the AFFOPID is compared with traditional PID and fractional order PID. The simulations show the effectiveness of the proposed adaptive fuzzy fractional order PID controller in terms of speed and steady-state error.